Typical sealant compositions which contain silanol-terminated diorganopolysiloxane or silylated polyurethane (SPUR) as base polymer, calcium carbonate as filler, a plasticizer for viscosity control, catalyst, cross-linker and adhesion promoter are inherently opaque. Moreover, fumed silicas are not typically used to any extent with the silanol-terminated diorganopolysiloxane without the polymer being endcapped due to the tendency of the free silanol (—SiOH) groups on the fumed silica to interact with the silanol terminated polymer thereby causing the formulation to increase in viscosity (structuring) during storage. In this regard, the structuring phenomenon limits the utility of fumed silica fillers, in any significant amount, in two-part silanol-terminated diorganopolysiloxane based sealant compositions.
Therefore, a need exists for stable translucent silicone compositions offering rapid primeness bond strength to a wide variety of substrates along with excellent physical properties. The invention disclosed herein provides stable translucent diorganopolysiloxane based silicone compositions and/or silylated polyurethane resin based compositions that are especially suitable as sealants or adhesives where the desired characteristics of high translucency, rapid primeness adhesion, strength and elasticity are important performance criteria.